Institute of Chemistry, St. Petersburg State University, 198504 St. Petersburg, Russia.
Molecules. 2020 Mar 19;25(6):1406. doi: 10.3390/molecules25061406.
An extensive series of 128 halogen-bonded complexes formed by trimethylphosphine oxide and various F-, Cl-, Br-, I- and At-containing molecules, ranging in energy from 0 to 124 kJ/mol, is studied by DFT calculations in vacuum. The results reveal correlations between R-X⋅⋅⋅O=PMe halogen bond energy Δ, X⋅⋅⋅O distance , halogen's σ-hole size, QTAIM parameters at halogen bond critical point and changes of spectroscopic parameters of phosphine oxide upon complexation, such as P NMR chemical shift, ΔP, and P=O stretching frequency, Δν. Some of the correlations are halogen-specific, i.e., different for F, Cl, Br, I and At, such as Δ(), while others are general, i.e., fulfilled for the whole set of complexes at once, such as Δ(ΔP). The proposed correlations could be used to estimate the halogen bond properties in disordered media (liquids, solutions, polymers, glasses) from the corresponding NMR and IR spectra.
通过 DFT 计算在真空条件下研究了由三甲基氧化膦和各种 F-、Cl-、Br-、I-和 At 含量分子形成的能量范围为 0 至 124 kJ/mol 的广泛的 128 个卤素键合复合物系列。结果揭示了卤素键能Δ、X⋅⋅⋅O 距离、卤素的 σ 空穴大小、卤素键临界点的 QTAIM 参数以及磷氧化物配合物后光谱参数变化（如 P NMR 化学位移ΔP 和 P=O 伸缩频率Δν）之间的相关性。其中一些相关性是卤素特异性的，即 F、Cl、Br、I 和 At 不同，而另一些则是普遍的，即适用于整个复合物集，例如Δ（ΔP）。可以从相应的 NMR 和 IR 光谱中使用这些提出的相关性来估计无序介质（液体、溶液、聚合物、玻璃）中的卤素键性质。
